So I’m about to do an air pollution test
I’m here at the I-5 overpass, and I’m getting small particle count readings of around 240
I'm one block away from the freeway, in a residential neighborhood,
and the particle counts are down to around 150,160.
The air we breathe depends on where we are.
These spots are only a block apart, but they have a big difference in air quality.
This is typical in any city: air quality can get 10 times worse in as little as a block.
But the tools we had weren’t designed to capture that level of detail.
Until now.
Cheap, portable air sensors have changed the way we see air pollution
They’re starting to open the door to a whole new type of air science.
And that’s allowing people to monitor the air at the community level.
But to understand why this matters, let’s start with this:
This is what a traditional air monitor looks like.
They’ve been the gold standard since the ‘50s and ‘60s.
These monitors suck air through a filter, and then weigh the dirty filter.
They give you a really accurate reading.
But that accuracy comes with its drawbacks: They’re huge.
You can’t move them around.
And they’re really expensive.
So most cities just have a few monitors, stationed across town.
You get a really accurate picture of certain areas, but miss a lot of that block-to-block detail.
Now if you were to add more sensors,
you could actually start to see a neighborhood’s air quality.
Or a block’s air quality.
So that’s where these come in!
These smaller air sensors have come onto the market over the past decade.
They shoot a laser through the air, and measure the light reflected off the particles.
It’s a tool that’s small and cheap.
So for the cost of one traditional air monitor, you can get 100 of these new, portable sensors.
That’s allowing regular people to start collecting data about the air they breathe.
I tagged along with a group of teenagers, using air sensors that they checked out
from a library.
It’s part of a program from the Puget Sound Clean Air Agency.
They lend out low-cost air sensors to citizen scientists and community groups.
And there’s similar programs in LA and Chicago.
We're able to lend these air sensors to people, they're able to monitor in their communities
and then start a dialogue with the people around them.
These teenagers are with the Service Board, a youth leadership nonprofit.
They’re collecting block-by-block air data in downtown Seattle,
nearby buses, idling trucks,
even this guy smoking a cigarette.
In the four blocks they sampled, they found the air quality varied a lot.
You might get minute data for 100 places,
whereas normally you would get hour data for 10 places.
You can use that to ask a lot of interesting questions about what the air quality is across the city.
And that's just starting to get investigated.
Capturing that variation is what the portable air sensors do best.
And understanding those details can have real impacts.
Take Seattle’s South Park Community Center.
It’s in an urban neighborhood surrounded by a lot of highway traffic and industry.
The quality of air, you can kind of see it.
You can taste it, so to speak.
So community members borrowed some air sensors.
And they found the air quality varied across the property. And it was worst at the playground.
Just the location of having the freeway so close to the playground.
It seemed like it wouldn’t make a good idea
Now, the community center has plans to remodel, and it’s going to move the playground
away from the freeway.
Understanding air pollution on a hyperlocal level can help communities make smarter decisions.
Still, these portable air sensors have their limits.
They just aren’t as accurate as traditional air monitors.
Ideally, they compliment each other, like a server vs a phone.
Air pollution is different from block to block and hour to hour.
It’s all the tailpipes, smokestacks, or even smokers around us.
Now, we have the tools to capture those variations.
And that means we have to potential to see and build our communities in healthier ways.